Atteintes du système nerveux central et infection par le VIH-1

Efficacy and safety of trimethoprim-sulfamethoxazole in HIV-infected patients with cerebral toxoplasmosis in Brazil: a single-arm open-label clinical trial

Cerebral toxoplasmosis continues to cause high morbidity and mortality in developing countries. The association of sulfadiazine and pyrimethamine is considered the standard therapy; however, it has potential disadvantages. This single-arm open-label clinical trial was carried out in a tertiary hospital in São Paulo, Brazil. We included patients of at least 18 years of age, whose HIV infection was confirmed, and clinical and brain computed tomography (CT) findings were compatible with cerebral toxoplasmosis upon admission. Patients received trimethoprim (TMP) 10 mg/kg/day sulfamethoxazole (SMX) 50 mg/kg/day, in two divided doses. Brain CT was performed at study entry and after two weeks. The endpoints of the study were: (i) the proportion of patients with clinical and radiological response after two weeks of TMP-SMX and (ii) the proportion of patients who discontinued TMP-SMX due to adverse events. Forty-six patients were included (23 males, median age 35 years). The main clinical manifestations were headache, hemiparesis and altered mental status. The proportion of patients who obtained clinical and radiological response after two weeks of anti-toxoplasma treatment was 85% (n = 39). Overall, TMP-SMX was safe, with only 2 (4%) discontinuations due to adverse events. In this study, TMP-SMX was effective and safe in the treatment of HIV-related cerebral toxoplasmosis.

HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease

Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.

Toxoplasmosis

Toxoplasma gondii, an Apicomplexan, is a pathogic protozoan that can infect the central nervous system. Infection during pregnancy can result in a congenial infection with severe neurological sequelae. In immunocompromised individuals reactivation of latent neurological foci can result in encephalitis. Immunocompetent individuals infected with T. gondii are typically asymptomatic and maintain this infection for life. However, recent studies suggest that these asymptomatic infections may have effects on behavior and other physiological processes. Toxoplasma gondii infects approximately one-third of the world population, making it one of the most successful parasitic organisms. Cats and other felidae serve as the definite host producing oocysts, an environmentally resistant life cycle stage found in cat feces, which can transmit the infection when ingested orally. A wide variety of warm-blooded animals, including humans, can serve as the intermediate host in which tissue cysts (containing bradyzoites) develop. Transmission also occurs due to ingestion of the tissue cysts. There are three predominant clonal lineages, termed Types I, II and III, and an association with higher pathogenicity with the Type I strains in humans has emerged. This chapter presents a review of the biology of this infection including the life cycle, transmission, epidemiology, parasite strains, and the host immune response. The major clinical outcomes of congenital infection, chorioretinitis and encephalitis, and the possible association of infection of toxoplasmosis with neuropsychiatric disorders such as schizophrenia, are reviewed.

Common clinical problems in children living with HIV/AIDS: systemic approach

Clinical manifestations in children living with HIV/ AIDS differ from those in adults due to poorly developed immunity that allows greater dissemination throughout various organs. In developing countries, HIV-infected children have an increased frequency of malnutrition and common childhood infections such as ear infections, pneumonias, gastroenteritis and tuberculosis. The symptoms common to many treatable conditions, such as recurrent fever, diarrhea and generalized dermatitis, tend to be more persistent and severe and often do not respond as well to treatment. The use of Anti Retroviral Therapy (ART) has greatly increased the long term survival of perinatally infected children so that AIDS is becoming a manageable chronic illness. As the immunity is maintained, the incidence of infectious complications is declining while noninfectious complications of HIV are more frequently encountered. Regular clinical monitoring with immunological and virological monitoring and the introduction of genotypic and phenotypic resistance testing where resources are available have allowed for dramatically better clinical outcomes. However, these growing children are left facing the challenges of lifelong adherence with complex treatment regimens, compounded by complex psycho-social, mental and neuro-cognitive issues. These unique challenges must be recognized and understood in order to provide appropriate medical management.

[Recurrent unilateral optic neuropathy associated with human immunodeficiency virus (HIV)]

HIV-related optic neuropathy is rare compared to optic neuropathies secondary to opportunistic infections in seropositive patients. We report the case of a 39-year-old HIV-positive woman referred for unilateral visual loss leading to the diagnosis of recurrent, unilateral, inflammatory optic neuropathy directly associated with HIV. Despite initial recovery after steroid treatment, she relapsed twice. Absence of any opportunist infections or toxic causes and presence of a very high viral load due to non-compliance with treatment led to the diagnosis of HIV-related optic neuropathy. Steroids and effective anti-retroviral treatment resulted in definitive and complete recovery. Inflammatory, degenerative and/or vascular mechanisms have been hypothesized to explain the occurrence of these rare HIV-related optic neuropathies. This diagnosis remains a diagnosis of exclusion to be considered in the work-up of seropositive patients with optic neuropathies.

Neurologic cytomegalovirus complications in patients with AIDS: retrospective review of 13 cases and review of the literature

Neurological disorders caused by Cytomegalovirus (CMV) in patients with Acquired Immunodeficiency Syndrome (AIDS) are rarely reported in the Highly Active Antiretroviral Therapy (HAART) period. The objective of this study was to describe the main clinical and laboratory features of patients with CMV-related neurological complications in HIV-infected patients admitted to a referral center in São Paulo, Brazil. CMV disease requires the identification of the virus in the cerebrospinal fluid (CSF) using Polymerase Chain Reaction (PCR). Thirteen cases were identified between January, 2004 and December, 2008. The median age of patients was 38 years and nine (69%) were men. At admission all patients were aware of their HIV status and only four (31%) patients were on HAART. Patients who were not on antiretroviral therapy before admission received HAART while inpatients. CMV disease was the first AIDS-defining illness in eight (62%) patients. The neurologic syndromes identified were diffuse encephalitis (n = 7; 62%), polyradiculopathy (n = 7; 54%), focal encephalitis (rhombencephalitis) (n = 1; 8%), and ventriculo-encephalitis (n = 1; 8%). Seven (54%) patients presented extra-neural CMV disease and four (31%) had retinitis. The median of CD4+ T-cell count was 13 cells/µL (range: 1-124 cells/µL). Overall in-hospital mortality was 38%. Eight patients used ganciclovir or foscarnet (in-hospital mortality: 50%) and five patients used ganciclovir and foscarnet (in-hospital mortality: 20%). None of the patients fulfilled the diagnosis criteria of immune reconstitution inflammatory syndrome. Four patients were lost to follow-up, and three patients presented immune recovery and discontinued secondary prophylaxis. Although infrequent, distinct neurological syndromes caused by CMV continue to cause high mortality among AIDS patients. Survival depends upon the use of effective antiviral therapy against CMV and the early introduction of HAART.

Toxoplasma gondii infection and cerebral toxoplasmosis in HIV-infected patients

Cerebral toxoplasmosis is a major cause of morbidity and mortality among HIV-infected patients, particularly from developing countries. This article summarizes current literature on cerebral toxoplasmosis. It focuses on: Toxoplasma gondii genetic diversity and its possible relationship with disease presentation; host responses to the parasite antigens; host immunosupression in HIV and cerebral toxoplasmosis as well as different diagnostic methods; clinical and radiological features; treatment; and the direction that studies on cerebral toxoplasmosis will likely take in the future.

Clinical cases where lesion therapy was chosen over deep brain stimulation

Deep brain stimulation (DBS) surgery has become the gold standard for treatment of select refractory cases of Parkinson disease and essential tremor. Despite the usefulness of DBS surgery in many cases, there remain situations where lesion therapy (subthalamotomy, pallidotomy or thalamotomy) may provide a reasonable alternative to DBS. We reviewed the University of Florida Institutional Review Board-approved database for movement disorders surgery and identified 286 DBS leads placed in 189 patients as well as 4 additional patients who had lesion therapy. In these 4 cases we reviewed the clinical presentations that resulted in a multidisciplinary team opting for lesion therapy over DBS. Lesion therapy represents a viable alternative and has several important advantages, including a decreased need for access to specialists and clinical follow-up, improved affordability, and a lower infection risk.

[Physiopathogenic aspects of HIV-associated primary brain lymphomas]

HIV-associated Primary brain lymphomas (PBLs) are usually diffuse, large B-cell lymphomas (DLBCLs). In contrast to those occurring in immunocompetent patients, nearly all HIV-associated PBLs are associated with Epstein-Barr virus (EBV). Since viral latency proteins are target antigens for anti-viral cytotoxic T lymphocytes, the double immunodeficiency (HIV infection, central nervous system microenvironment) favors the expression of viral latency proteins (LMP-1, EBNA2). These proteins play a major role in immortalization and transformation of infected B lymphocytes through cell cycle activation and apoptosis inhibition.